mac80211: Add new callback set_coverage_class

Mac80211 callback to driver set_coverage_class() sets slot time and ACK
timeout for given IEEE 802.11 coverage class. The callback is optional,
but it's essential for long distance links.

Signed-off-by: Lukas Turek <8an@praha12.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index 977cc75..0ea2581 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -491,6 +491,29 @@
 	)
 );
 
+TRACE_EVENT(drv_set_coverage_class,
+	TP_PROTO(struct ieee80211_local *local, u8 value, int ret),
+
+	TP_ARGS(local, value, ret),
+
+	TP_STRUCT__entry(
+		LOCAL_ENTRY
+		__field(u8, value)
+		__field(int, ret)
+	),
+
+	TP_fast_assign(
+		LOCAL_ASSIGN;
+		__entry->ret = ret;
+		__entry->value = value;
+	),
+
+	TP_printk(
+		LOCAL_PR_FMT " value:%d ret:%d",
+		LOCAL_PR_ARG, __entry->value, __entry->ret
+	)
+);
+
 TRACE_EVENT(drv_sta_notify,
 	TP_PROTO(struct ieee80211_local *local,
 		 struct ieee80211_sub_if_data *sdata,